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    <title>Document</title>
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            html{
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        .box{
            width: 46.875rem;
            height: 6.25rem;
            background-color: yellow;
            /* font-size: .75rem; */
        }
        /* body{
            font-size: 1rem;
        } */
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    <script>
        //  fontsize 计算
        document.documentElement.style.fontSize = document.documentElement.clientWidth/750*20+'px'

        // dontsize = 当前设备的css布局宽度/物理分辨率(设计稿宽度)*基准 font-size
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    <div class="box">

        的换届大会几点回家

    </div>
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